The present invention relates to a cathode ray tube, and more particularly to a cathode ray tube which prevents the mislanding of the electron beam emitted from an electron gun and intended for the corner areas of a fluorescent layer, after colliding with the inner surface of the funnel.
Generally, a cathode ray tube as shown in FIG. 1, comprises a panel 10 on whose inner surface is formed a fluorescent layer 11, and a funnel 20 connected to panel 10 and including an electron gun 22 mounted inside a neck portion 21 and a deflection yoke 23 installed around the cone portion near the neck portion. In the cathode ray tube of FIG. 1, an electron beam emitted from electron gun 22 is deflected by deflection yoke 23 according to the scanning position on fluorescent layer 11, to land on fluorescent layer 11 and thus form a pixel; many such pixels are gathered to form a picture. However, since the screen is elongated in the horizontal direction, the deflection angle is enlarged, so that the electron beam emitted from electron gun 22 collides with the inner surface of funnel 20 and cannot be precisely landed in the corner areas of fluorescent layer 11. The collision against the inner surface of funnel 20 by the electron beam emitted from electron gun 22 and intended for the corner areas of fluorescent layer 11, is due to the shape of funnel 20, installation conditions of deflection yoke 23, positioning of electron gun 22 and deflection yoke 23, etc. If, to solve the above problems, the cone portion near the neck of funnel 20 is formed such that it is large enough for the electron beam to avoid the above-described collision, the cathode ray tube must be enlarged accordingly, which necessitates that each part thereof be designed differently. Particularly, a cathode ray tube so enlarged significantly increases the process time required to adequately vacuumize its interior.